Question 1

______have lost,through ______,the ability to grow on minimal medium.

Accepted Answer

A)  prototrophs; adaptation
B)  mutants; adaptation
C)  prototrophs; mutation
D)  auxotrophs; mutation
E)  auxotrophs; adaptationF) A) and E)
G) A) and C)

Question 2

What is a bacteriophage?

Accepted Answer

A)  a bacterium that infects other bacteria
B)  a bacterium that infects a virus
C)  a virus that exclusively undergoes the lytic cycle
D)  a virus that exclusively undergoes the lysogenic cycle
E)  a virus that has a bacterium as its hostF) A) and D)
G) B) and E)

Question 3

______can exist integrated into the bacterial chromosome or as an autonomous plasmid unit in the cytosol.

Accepted Answer

A)  Col plasmid
B)  Temperate phages
C)  Episomes
D)  F' plasmid
E)  R factorF) A) and D)
G) None of the above

Question 4

In a mixed infection experiment,you study two plaque phenotypes of large l+ versus small l- and bumpy b+ versus smooth b- .You mix small l- b+ with smooth l+ b- and identify 50 small,smooth and 47 large,bumpy.How far apart are the genes?

Accepted Answer

A)  490
B)  99
C)  49
D)  1000
E)  There is not enough information to calculate the distance.F) B) and E)
G) C) and E)

Question 5

Name the general category into which double- stranded circular extrachromosomal DNA elements such as F factors,ColE1,and R would fall.

Accepted Answer

A)  r- determinant
B)  plaque
C)  partial diploid
D)  capsid
E)  plasmidF) A) and E)
G) C) and D)

Question 6

A form of bacterial recombination that involves a viral intermediate is called ______.

Accepted Answer

A)  plaque assay
B)  transduction
C)  transformation
D)  conjugation
E)  competencyF) All of the above
G) None of the above

Question 7

Which of the following statements is false?

Accepted Answer

A)  A symbiotic relationship between a phage and a bacterium apparently occurs in the process of lysogeny.
B)  Lysogeny is a process that occurs during transformation and conjugation.
C)  A bacteriophage that can only undergo lysis is called a virulent phage.
D)  A prophage can exist in a quiescent state in the bacterial chromosome.
E)  Viral genomes comprise only genes for viral structure and assembly.F) A) and E)
G) A) and D)

Question 8

What is the process by which a temperate bacteriophage infects a bacterial cell and subsequently integrates its chromosome into the bacterial chromosome?

Accepted Answer

A)  lysogeny
B)  transduction
C)  temperate
D)  transformation
E)  lysisF) A) and D)
G) A) and B)

Question 9

A bacteriophage that is capable of entering either a lytic or a lysogenic cycle is called an______.

Accepted Answer

A)  temperate bacteriophage
B)  virulent bacteriophage
C)  plasmid
D)  plaque- forming unit
E)  episomeF) B) and D)
G) A) and D)

Question 10

What is the adaptation hypothesis?

Accepted Answer

A)  The bacteria will mutate so it can become an auxotroph.
B)  The phage mutates to infect bacteria more effectively.
C)  The phage mutates so it can't infect bacteria any longer.
D)  The phage and bacteria both mutate so the phage becomes less virulent.
E)  The phage stimulates the bacteria to mutate to become immune to the phage.F) A) and C)
G) B) and D)

Question 11

Transduction is a form of recombination in bacteria that involves______ .

Accepted Answer

A)  fertility factors
B)  physical contact between the bacteria involved
C)  plasmids
D)  5- bromouracil
E)  bacteriophagesF) A) and D)
G) A) and E)

Question 12

Which of the following occurs during cell lysis?

Accepted Answer

A)  prophage formation
B)  plaque formation
C)  lysogeny
D)  binary fission
E)  episome propagationF) B) and E)
G) A) and C)

Question 13

Bacteria that are in a particular physiological state to become transformed are called______ .

Accepted Answer

A)  resistant
B)  episomal
C)  transformable
D)  temperate
E)  competentF) A) and B)
G) B) and D)

Question 14

What is the first step in phage formation inside the bacterial cell?

Accepted Answer

A)  tail formation
B)  tail fibers are added
C)  DNA packaging as the viral heads assemble
D)  adherence to the pilus
E)  lysisF) A) and B)
G) B) and E)

Question 15

Temperate phages are those that can enter either the______ or the______ cycle.

Accepted Answer

A)  functional; nonfunctional
B)  complementing; competing
C)  virulent; avirulent
D)  former; nonformer
E)  lytic; lysogenicF) C) and D)
G) B) and E)

Question 16

In a mixed infection experiment,the results of an h+r and hr+ cross are as follows.   How far apart are these two genes?

Accepted Answer

A)  12
B)  24
C)  48
D)  8
E)  2F) B) and C)
G) A) and B)

Question 17

Name two forms of recombination in bacteria.

Accepted Answer

A)  auxotrophic and prototrophic
B)  conjugation and transduction
C)  lytic and lysogenic
D)  insertion and replication
E)  mixed and generalizedF) B) and E)
G) B) and D)

Question 18

Which of the following is an episome?

Accepted Answer

A)  F factor and temperate phage
B)  lytic phage
C)  F factor
D)  temperate and lytic phages
E)  temperate phageF) A) and D)
G) None of the above

Question 19

Assume that one counted 67 plaques on a bacterial plate where 0.1 ml of a 10-5 dilution of phage was added to bacterial culture.What is the initial concentration of the undiluted phage?

Accepted Answer

A)  6.7 × 10-5 pfu/ml
B)  0.1 × 105 pfu/ml
C)  6.7 × 105 pfu/ml
D)  67 pfu/ml
E)  6.7 × 107 pfu/ml pfu = plaque- forming units F) A) and C)
G) A) and D)

Question 20

How do different strains of E.coli can reveal different linkage arrangements of genes in Hfr crosses?

Accepted Answer

A)  They do not.All Hfr strains are identical.
B)  Different strains may have different F factors and therefore different initiation points for chromosome transfer.
C)  Hfr strains will demonstrate different areas of recombination,due to dominance and recessiveness of genes.
D)  In different Hfr strains,different genes will be transferred based on where the centromere resides.
E)  In different Hfr strains,genes can be in different order on the chromosome.F) C) and D)
G) A) and D)

Exam 6: Genetic Analysis and Mapping in Bacteria and Bacteriophages

Temperate phages are those that can enter either the______ or the______ cycle.

Correct AnswerverifiedShow Answer

In a mixed infection experiment,the results of an h+r and hr+ cross are as follows. How far apart are these two genes?

Correct AnswerverifiedShow Answer

Assume that one counted 67 plaques on a bacterial plate where 0.1 ml of a 10-5 dilution of phage was added to bacterial culture.What is the initial concentration of the undiluted phage?

Correct AnswerverifiedShow Answer

A form of bacterial recombination that involves a viral intermediate is called ______.

Correct AnswerverifiedShow Answer

Bacteria that are in a particular physiological state to become transformed are called______ .

Correct AnswerverifiedShow Answer

Name two forms of recombination in bacteria.

Correct AnswerverifiedShow Answer

______have lost,through ______,the ability to grow on minimal medium.

Correct AnswerverifiedShow Answer

Name the general category into which double- stranded circular extrachromosomal DNA elements such as F factors,ColE1,and R would fall.

Correct AnswerverifiedShow Answer

______can exist integrated into the bacterial chromosome or as an autonomous plasmid unit in the cytosol.

Correct AnswerverifiedShow Answer

Which of the following is an episome?

Correct AnswerverifiedShow Answer

How do different strains of E.coli can reveal different linkage arrangements of genes in Hfr crosses?

Correct AnswerverifiedShow Answer

What is the adaptation hypothesis?

Correct AnswerverifiedShow Answer

What is the first step in phage formation inside the bacterial cell?

Correct AnswerverifiedShow Answer

Which of the following occurs during cell lysis?

Correct AnswerverifiedShow Answer

A bacteriophage that is capable of entering either a lytic or a lysogenic cycle is called an______.

Correct AnswerverifiedShow Answer

What is the process by which a temperate bacteriophage infects a bacterial cell and subsequently integrates its chromosome into the bacterial chromosome?

Correct AnswerverifiedShow Answer

What is a bacteriophage?

Correct AnswerverifiedShow Answer

In a mixed infection experiment,you study two plaque phenotypes of large l+ versus small l- and bumpy b+ versus smooth b- .You mix small l- b+ with smooth l+ b- and identify 50 small,smooth and 47 large,bumpy.How far apart are the genes?

Correct AnswerverifiedShow Answer

Which of the following statements is false?

Correct AnswerverifiedShow Answer

Transduction is a form of recombination in bacteria that involves______ .

Correct AnswerverifiedShow Answer

Temperate phages are those that can enter either the or the cycle.

Correct Answer
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Assume that one counted 67 plaques on a bacterial plate where 0.1 ml of a 10^-5dilution of phage was added to bacterial culture.What is the initial concentration of the undiluted phage?

Correct Answer
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have lost,through ,the ability to grow on minimal medium.

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In a mixed infection experiment,you study two plaque phenotypes of large l⁺ versus small l^- and bumpy b⁺ versus smooth b^- .You mix small l^-b⁺ with smooth l⁺b^- and identify 50 small,smooth and 47 large,bumpy.How far apart are the genes?

Correct Answer
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